Block 3

• Introduction to the Digestive Tract

  • Vicki Waring
  • [e-mail]
  • Andrei Ștefan
  • [e-mail]
• Prehension and Mastication


  • Lips
  • Teeth
  • Tongue
  • Salivary glands
  • Musculature
• Salivary glands


  • Stenon
  • Nück
  • Wharton
  • Bartholin
  • Rivinius
• Stomach


  Stomach Histology
• Stomach Histology


  • 50 µm
  • gastric glands
  • lamina muscularis
  • three layers of smooth muscle
  • blood vessel
• Small Intestine


  • Duodenum
  • Lining secretes mucous and fluids
  • Bile duct
  • Pancreatic duct
  • Jejunum and Ileum
  • Secretes fluids
  • Digestive
  • Absorptive
  • serosa
  • tunica muscularis
  • submucosa
  • mucosa
  • villi
• Caecum & Colon (Large Intestine)


  • Caecum > Ascending Colon > Transverse Colon > Descending Colon > Rectum
  • Absorb water and ions
  • compaction of undigested material and microflora
  • Expel faeces via rectum and anus
• Caecum & Colon (Large Intestine) Histology


  • 0.5 mm
  • lumen
  • mucosa
  • submucosa
  • tunica muscularis
  • serosa
• Liver


  • Synthesis of bile
  • Storage
  • Biotransformation
  • Synthesis of blood components
• Liver Histology

  • 250 µm
  • central vein
  • portal areas
  • liver lobules
  • Bile duct
  • Portal arteriole
  • Portal venule
  • sinusoid
• Pancreas

  • 100 µm
  • pancreatic acini
  • exocrine pancreas
  • islet of Langerhans
  • endocrine pancreas
  • interlobular duct
  • blood vessel
  • Exocrine - secretes digestive enzymes into duodenum
  • Endocrine - produces and releases hormones into blood stream
• Blood Supply

  • Coeliac Artery
  • Cranial and Caudal Mesenteric Artery
• Venous Drainage

  • Portal Vein
• Nerve Supply

  • Somatic innervation to body wall
  • Autonomic Innervation to viscera
  • Parasympathetic - increases digestive processes
  • Sympathetic - Decreases digestive processes
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